After Gastil's post I found this:
http://nps.gov/redw/naturescience/…
So it seems that they think they have T. chloropetalum.
A couple of years ago a friend and I tried to key out some Trillium
we thought were T. chloropetalum after adding them to the wiki under
that name and getting an email saying we were wrong. We used three
keys and found nothing matched perfectly, but finally decided that
what we were seeing was probably Trillium albidum. There was a lot of
variation in the populations and some of the flowers were pink.
I'll include what I wrote afterwards showing how challenging it is
sometimes to come up with a correct identification from a photo and
even when you have the plant in front of you. Often photos don't show
the important identifying features.
"Flora of the Sonoma County key:
Flowers with portion of the filament joining the 2 cells of an anther
greenish; filament usually green, sometimes purple, anther dehiscence
lateral; tepals white (rarely purple basally) to pink -- T. albidum
Flowers with stamens and anthers purple throughout; anther dehiscence
turned inward; tepals varying from purple to yellow or white -- T.
chloropetalum
Flowers in the first one we looked at from one population had purple
filaments and the direction of the anthers was a bit uncertain. They
didn't really look lateral, but weren't entirely turned inward
either. Flowers in a second population several people have been sure
was T. chloropetalum also had purple filaments. These anthers turned
inward. The anthers were not purple however in either population.
They were greenish.
Plants of the SF Bay region key:
Petals whitish, yellowish, or dark purple; fruiting portion of pistil
purplish; top of the filaments between the anther sacs purplish --
Trillium chloropetalum
Petals white to pink; fruiting portion of pistil usually green, but
sometimes slightly tinged with purple, tip of filaments, between the
anther sacs, green -- Trilium albidum In both populations the
fruiting portion of the pistil was purplish and the top of the filaments purple
Jepson (this was before the new version came out):
Ovary and tissue between anther sacs greenish; petals white to pink
(base sometimes purplish) - T. albidum Ovary and tissue between
anther sacs purple; petals yellow to purple, sometimes white - T.
chloropetalum The tissue between anthers sacs was greenish, not
purple. However, the ovaries of one of the populations were green and
the ovaries of the other population were purple, except for four
plants with green ovaries. This was a very large population of plants
and only the four plants had green ovaries, but it made us wonder if
the color of the ovary was really a defining characteristic.
The descriptions in Jepson says that sometimes T. albidum can have
purplish ovaries."
We consulted a friend who had recently worked on this same issue in
another part of Sonoma county and she said she thought the color of
the anther sacs was the crucial character. After we figured out what
the anther sacs were, we found there were green so concluded that
they were both T. albidum even though the one population had always
been identified at T. chloropetalum. So the identification of the
flowers got changed on the wiki. I never got around to adding my
photos that showed some of this more clearly, but I should do so one
of these days.
However, I shared this with another plant expert in our area and he
shared a quote from someone from the Jepson Herbarium that I really
like: "just because something keys to something, it doesn't mean it
is that something!"
Mary Sue